Conventionally, a refrigeration cycle is used in an air conditioner. It is considered to perform a specific cooling operation on a condition that the refrigeration cycle is stopped. For example, a compressor in the refrigeration cycle is driven by an engine for moving a vehicle in a vehicle air conditioner. The refrigeration cycle is thereby stopped when the engine is stopped while the vehicle is stopping moving temporarily.
For a purpose of performing a specific cooling operation while the vehicle is stopping moving, it is disclosed that a heat exchanger has a cold heat storage body storing a cold heat in an evaporator disposed in the refrigeration cycle (refer to e.g., Patent Literature 1). The heat exchanger disclosed in Patent Literature 1 has, as a cold heat storage body, a solid-liquid phase transitional latent heat storage body.